javascript - consuming json with jquery ? .getJSON callback does not fire -

i've got cs webservice returns json when passed id: "jdoe"

<?xml version="1.0" encoding="utf-8"?> <string xmlns="http://tempuri.org/">[{"department":"sales","mail":"jdoe@acme.com"}]</string> 

i'm looking minimal jquery code display department , trying this:

$(document).ready(function () {     url = "http://test.mydomain.com/webservice.asmx/getdept?callback=?"     alert("start");     $.getjson( url, { id: "jdoe" }, function( data ) {  alert(data.department); });     alert("end"); }); 

i see alerts start , end.

i've checked fiddler , not see errors call made.

on local webserver prompted id , return expected json.

my cs looks this:

    public string getdept(string id) {     var json = "";     var umid  = result in dc.get_dept(id) select result;      javascriptserializer jss = new javascriptserializer();      json = jss.serialize(id);      return json; 

the problem that

<?xml version="1.0" encoding="utf-8"?> <string xmlns="http://tempuri.org/">[{"department":"sales","mail":"jdoe@acme.com"}]</string> 

is xml json string inside. code work, need pass back:

[{"department":"sales","mail":"jdoe@acme.com"}] 

on own.